This invention relates generally to concrete placing devices and, more particularly, to a low profile concrete placing and screeding apparatus for placing concrete in floors of buildings or in other areas where overhead obstructions preclude or limit the use of a boom truck.
It is known to use a pumping truck and pipe or a boom truck to place concrete at a targeted site. The boom truck, which comprises an articulated boom and pipe apparatus, where the pipe sections are pivotable about one or more generally horizontal axes, may be used to reach areas which are at a greater distance from the pumping truck or which are at a different height, such as an upper floor of a building or the like. However, it is difficult to use conventional boom trucks between floors of buildings because there may not be enough clearance between the floor and the overhead structures to reach the entire floor with the boom. The boom of the boom truck may also not be sufficiently long to reach distant areas of the targeted floor, thus requiring additional pipes to carry and place the concrete at those areas. An additional concern with boom trucks is that these trucks are typically too heavy to be driven onto raised or elevated slabs in order to be able to reach upper floors or levels of buildings.
In areas where boom trucks cannot reach or where a pumping truck is available while a boom truck is not, a movable pipe or multiple sections of pipe may be connected to the concrete pump and extended therefrom in order to reach the targeted area. Although such systems are capable of reaching remote areas from the pumps, it is difficult to manage the large and heavy pipes in order to properly place the concrete. Although several devices have been proposed which provide a mounting base for a movable pipe assembly to pivotally extend therefrom, it is still difficult to manage such devices, since the base must be manually moved once the pipes have spread the concrete at each particular location.
Additionally, after the pumping truck or boom truck has placed the concrete at the targeted areas via pipes or a boom, a screeding device must be positioned at the targeted areas to compact and smooth the concrete before it cures. Typically, the concrete may be placed in a targeted region of a floor and then the screeding device may be positioned at this region to smooth and pack the concrete while the placing system is moved to the next targeted region. This may require further movement of the placing apparatus in order to make room for the screeding apparatus, prior to placing the concrete at the next, typically adjacent, targeted location.
Accordingly, there is a need in the art for a low-profile placing apparatus which is easy to manage and/or maneuver in areas where there is low overhead clearance. The apparatus must be capable of reaching areas of a construction site which are remote from the location of a pumping truck. Additionally, the apparatus must be of relatively low weight, in order to be operable on raised or elevated slabs so as to be able to place concrete on upper floors or levels of buildings. There is also a need for an improved, more efficient method and apparatus for screeding the poured and/or placed concrete in such remote, difficult to reach areas, especially where overhead clearance is low, or on raised, elevated slabs.
The present invention is intended to provide a concrete placing and screeding apparatus which is especially useful and operable in areas with low overhead clearance, or on raised, elevated slabs, or in other locations where the support of high weight apparatus is difficult. The apparatus is easily maneuverable to place the appropriate amount of concrete in each targeted area. Additionally, a screeding device may be implemented with the placing apparatus, in order to combine the placing and screeding operations.
According to a first aspect of the present invention, a concrete placing apparatus for placing uncured concrete at a support surface comprises a conduit having a supply end and a discharge end, a movable wheeled base unit which supports the supply end of the conduit and a movable wheeled support unit which movably supports the discharge end of the conduit. The supply end of the conduit is adaptable to receive a supply of uncured concrete, while the discharge end is adapted to discharge the uncured concrete onto the support surface. At least one of the movable wheeled units includes a frame and two wheels which are adjustably mounted to the frame. The two wheels are adjustable between a laterally outward position and laterally inward position relative to frame. The concrete placing apparatus thus may be reduced in size via adjusting the wheels to their laterally inward position and retracting the extendable conduit to a retracted position, such that the concrete placing apparatus may be easily maneuverable and transportable between worksites.
In one form, the wheels of wheeled units are adjustable relative to the frame via pivotal movement of the wheels about a generally vertical pivot axis at opposite sides of the frames. The wheels are correspondingly adjustable about their respective vertical pivot axes to steer the wheeled units over the support surface. The wheels may be pivotally adjusted via a double ended hydraulic cylinder, where one end of the cylinder extends and retracts to pivot one of the wheels relative to the frame and the other end of the hydraulic cylinders correspondingly retracts and extends to pivot the other one of the wheels relative to the frame. Preferably, each of the wheels are independently drivable.
The conduit is preferably an extendable conduit and is extendable and retractable to adjust an overall length or reach of the placing apparatus. The extendable conduit has at least two sections which are extendable and retractable relative to one another. In one form, the extendable conduit has three sections. The extendable conduit is extendable and retractable by an extension and retraction device which preferably is operable to extend and retract the three sections generally correspondingly with respect to one another. The extension and retraction device may extend a middle section relative to an inner section via a rotatable drive member rotating along a track secured to the base unit, while a pulley system is operable to cause corresponding movement of the outer section relative to the middle section.
The concrete placing apparatus may further include a screeding device or plow assembly for at least partially smoothing and spreading out the uncured concrete over the support surface after the uncured concrete has been discharged by the placing apparatus. The discharge end of the conduit may further include a discharge tube, which may be flexible or curved to swing or move a discharge end of the flexible tube arcuately back and forth with respect to the wheeled support unit. The plow assembly may also be mounted to the support unit and may be laterally movable with the discharge end of the discharge tube. In one form, the plow assembly may include a plow which is movable back and forth to smooth or spread the uncured concrete in either direction. The plow assembly may also be vertically adjustable relative to the support unit and may be vertically adjustable in response to a laser leveling system.
According to another aspect of the present invention, a method for placing uncured concrete at a support surface comprises providing a concrete placing apparatus which includes a two-wheeled base unit and a two-wheeled support unit. The two-wheeled unit support opposite portions of an extendable conduit assembly. The lateral position of each of a pair of wheels for each of the two-wheeled units is adjustable between a laterally inward state and a laterally outward state. A supply of uncured concrete is connected to a supply end of the extendable conduit. The uncured concrete is discharged from a discharge end of the extendable conduit onto the support surface. The at least two-wheeled units are moved while discharging the uncured concrete over the support surface.
The lateral position of the pair of wheels for each of the wheeled units is adjustable to facilitate transportation and movement of the concrete placing apparatus over the support surface. When positioned in the laterally inward state, the concrete placing apparatus has a relatively narrow profile, which allows the apparatus to fit within a conventional manlift or the like to facilitate movement of the apparatus between worksites or elevated floors or decks without requiring complete disassembly of the apparatus.
According to a another aspect of the present invention, a concrete placing device for placing uncured concrete at a support surface comprises a base unit, a conduit, and a movable support. The conduit comprises a supply end and a discharge end, wherein the discharge end comprises a discharge outlet and is generally opposite the supply end. The supply end is mounted to the base unit and is connectable to a supply of uncured concrete. The conduit is operable to dispense the uncured concrete through the discharge outlet. The movable support is operable to movably support the discharge end of the conduit at a position remote from the base unit. Preferably, the conduit is an extendable tube which is extendable and retractable relative to the base unit. Preferably, the base unit comprises a base portion and a swivel portion rotatably supported by the base portion. The supply end of the extendable tube is mounted to the swivel portion, such that the discharge end of the extendable tube is movable arcuately and/or radially relative to the base unit. Preferably, the concrete placing device further comprises a screeding device positioned at the discharge end of the conduit.
In one form, the movable support comprises a wheeled vehicle, preferably having four wheels. In another form, the movable support comprises an air cushion device. In yet another form, the movable support comprises a plurality of wheel trolleys which are rotatable about a generally closed path via a drive motor and drive member such that the trolleys and the movable support are movable in a direction generally axially relative to the wheels of the wheel trolleys.
According to another aspect of the present invention, a concrete placing and screeding apparatus comprises a movable support, a conduit having a supply end and a discharge end, and a screeding device at the discharge end of the conduit. The supply end of the conduit is generally opposite the discharge end and is connected to a supply of uncured concrete to be placed. The conduit is supported by the movable support.
According to yet another aspect of the present invention, a concrete apparatus for placing and/or screeding uncured concrete at a support surface comprises one or both of a concrete supply unit and/or a screeding device, as well as an air cushion support unit. The concrete supply unit provides uncured concrete to the support surface, while the screeding device is operable to grade and smooth the uncured concrete on the support surface. The air cushion support unit is operable to support one or both of the concrete supply unit and/or the screeding device.
In one form, the concrete supply unit comprises a conduit having a supply end for receiving uncured concrete for discharging the uncured concrete on the support surface. Preferably, the conduit is extendable between the extended and retracted position relative to a base unit. The extendable conduit may be a telescopingly extendable tube, which is mounted to a pivotable base unit. The extendable conduit may otherwise be an articulated tube which comprises at least two sections which are pivotable about a joint, with the supply end of the conduit being mounted to a generally fixed base unit. The conduits, support units and/or base units are operable to move the discharge end of the conduit and/or the screeding device both arcuately and radially with respect to the base unit.
According to yet another aspect of the present invention, a concrete placing apparatus for placing uncured concrete at a support surface comprises an extendable conduit having a supply end and a discharge end, at least one air cushion support unit, which is operable to support the extendable conduit, and a base unit which is operable to support the supply end of the extendable conduit. The extendable conduit is operable to receive a supply of uncured concrete and discharge the uncured concrete to the support surface via the discharge end of the conduit.
In one form, the base unit is substantially fixed, and may be secured via two or more adjustable cables. Preferably, the extendable conduit is an articulated conduit having at least two sections pivotable about a generally vertically axis relative to one another. In one form, the articulated conduit may comprise at least three sections, with at least two air cushion supports supporting two of the sections of the conduit. In another form, the conduit may be flexible in a horizontal direction, while substantially precluding upward and downward flexing, such that the conduit may be bent or pivoted relative to the base unit about one or more generally vertical axes.
In another form, the extendable conduit may be telescopingly extendable to radially extend and retract the discharge end with respect to the base unit. The extendable conduit may further be arcuately movable with respect to the base unit.
Preferably, the extendable conduit is mounted to the air cushion support with a trunnion which allows for pivotal movement of the extendable conduit about a generally horizontal axis, while also allowing pivotal movement of the conduit about an axis extending generally along the extendable conduit.
Accordingly, the present invention provides a placing and/or screeding apparatus which is easily maneuverable and which may be easily implemented in areas where a boom truck cannot reach, such as remote areas of buildings or areas with low overhead clearance, or raised or elevated decks or slabs where weight may be a concern. The pivotable wheels allow for the placing apparatus to be adjusted between a narrow profile apparatus for moving the apparatus to a work site and a wider profile apparatus for greater stability of the apparatus at the work site. The air cushion devices function to movably support the concrete supply and/or a screeding device and spread the load of the units over a larger area via a cushion of air, such that the pressure exerted by the movable units on the support surface is substantially reduced. The air cushion units also facilitate movement of the conduit and/or screeding device over areas which are already covered with uncured concrete, such that concrete may be placed or smoothed in those areas without disturbing the already placed uncured concrete. The conduits are preferably extendable and may be extended and retracted relative to a base unit, such that the discharge end of the conduit and/or the screeding device may be moved throughout the targeted area to place or screed concrete in substantially all locations within the targeted area.
These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.